Implement HKDF for WebCrypto (blink-side)

Source/modules/crypto/NormalizeAlgorithm.cpp

Index: Source/modules/crypto/NormalizeAlgorithm.cpp
diff --git a/Source/modules/crypto/NormalizeAlgorithm.cpp b/Source/modules/crypto/NormalizeAlgorithm.cpp
index 823989554d1830bcbaa42b07280068057277d59b..cd540a563040a4e438fedb95f935847395295ee2 100644
--- a/Source/modules/crypto/NormalizeAlgorithm.cpp
+++ b/Source/modules/crypto/NormalizeAlgorithm.cpp
@@ -67,6 +67,7 @@ struct AlgorithmNameMapping {
 // Also all names must be upper case ASCII.
 const AlgorithmNameMapping algorithmNameMappings[] = {
     {"HMAC", 4, WebCryptoAlgorithmIdHmac},
+    {"HKDF", 4, WebCryptoAlgorithmIdHkdf},
     {"ECDH", 4, WebCryptoAlgorithmIdEcdh},
     {"SHA-1", 5, WebCryptoAlgorithmIdSha1},
     {"ECDSA", 5, WebCryptoAlgorithmIdEcdsa},
@@ -773,6 +774,37 @@ bool parseAesDerivedKeyParams(const Dictionary& raw, OwnPtr<WebCryptoAlgorithmPa
     return true;
 }
 
+// FIXME: once the spec has been updated, check that the implementation is
+// still correct and update this comment. http://crbug.com/399095
+//
+// The WebCrypto spec hasn't been updated yet to define HKDF
+// (https://www.w3.org/Bugs/Public/show_bug.cgi?id=27425). The assumed
+// parameters are:
+//
+//    dictionary HkdfParams : Algorithm {
+//      required HashAlgorithmIdentifier hash;
+//      required BufferSource salt;
+//      required BufferSource info;
+//    };
+bool parseHkdfParams(const Dictionary& raw, OwnPtr<WebCryptoAlgorithmParams>& params, const ErrorContext& context, AlgorithmError* error)
+{
+    WebCryptoAlgorithm hash;
+    if (!parseHash(raw, hash, context, error))
+        return false;
+    BufferSource saltBufferSource;
+    if (!getBufferSource(raw, "salt", saltBufferSource, context, error))
+        return false;
+    BufferSource infoBufferSource;
+    if (!getBufferSource(raw, "info", infoBufferSource, context, error))
+        return false;
+
+    DOMArrayPiece salt(saltBufferSource);
+    DOMArrayPiece info(infoBufferSource);
+
+    params = adoptPtr(new WebCryptoHkdfParams(hash, salt.bytes(), salt.byteLength(), info.bytes(), info.byteLength()));
+    return true;
+}
+
 bool parseAlgorithmParams(const Dictionary& raw, WebCryptoAlgorithmParamsType type, OwnPtr<WebCryptoAlgorithmParams>& params, ErrorContext& context, AlgorithmError* error)
 {
     switch (type) {
@@ -823,6 +855,9 @@ bool parseAlgorithmParams(const Dictionary& raw, WebCryptoAlgorithmParamsType ty
     case WebCryptoAlgorithmParamsTypeAesDerivedKeyParams:
         context.add("AesDerivedKeyParams");
         return parseAesDerivedKeyParams(raw, params, context, error);
+    case WebCryptoAlgorithmParamsTypeHkdfParams:
+        context.add("HkdfParams");
+        return parseHkdfParams(raw, params, context, error);
     }
     ASSERT_NOT_REACHED();
     return false;